1. Field of the Invention:
The invention relates to an ink ribbon cartridge for use in an impact printer.
2. Description of the Prior Art:
Known ink ribbon cartridges for use in impact printers include a cartridge case having a storage space and an endless ink ribbon folded in the storage space. The endless ink ribbon has a portion drawn out of the storage space by and between the distal ends of a pair of ribbon guide arms projecting from a front portion of the cartridge case. The drawn ink ribbon portion is positioned between a print head and a print sheet, and desired characters are printed by the print head on the print sheet through the ink ribbon. In the cartridge case, the ink ribbon is gripped by a pair of rollers which are rotated to pull the ink ribbon so as to guide the same into the storage space.
The aforesaid ink ribbon cartridge is disclosed in Japanese Patent Publication No. 57-22026 published on May 11, 1982 and Japanese Laid-Open Utility Model Publication No. 57-57954 published on Apr. 5, 1982.
When the conventional ink ribbon cartridge is in storage or is not in use for a long time, the same portion of the ink ribbon remains gripped by the rollers and tends to stick to them. At the time the rollers are rotated when the ribbon cartridge is in use, the ink ribbon is liable to be wound around the rollers, resulting in an ink ribbon jam. Furthermore, the ink may be squeezed out of the ink ribbon where it is gripped by the rollers. When characters are printed by the squeezed portion of the ink ribbon, the printing density is reduced and the printed characters may not be readable.